Finger units used in robot hands are typically of a multi-joint construction. Multi-joint finger units must be small-sized and lightweight in order for them to be capable of performing actions of gripping, picking, and throwing physical objects reliably at high speed.
Finger units used for such purposes and palm mechanisms for robot hands in which such units are employed are disclosed in Patent References 1 and 2 below.
[Patent Reference 1] JP-A 2004-122339
[Patent Reference 2] JP-A 2004-181610
Bevel gears are used in joint sections in the finger units described in the above patent references. A linking member is attached to a rotating shaft of the bevel gears in a position between bearings that support the rotating shaft. A finger body is attached to a forward end of the linking member. The finger body is caused to swivel around the rotating shaft of the bevel gears.
The robot hand may be used in an environment wherein thick powder dust is present. In such cases, foreign matter enters from the outside into a section where the bevel gears mesh and into a bearing section of the rotating shaft of the bevel gears. These sections constitute joint sections of the finger units of the robot hand. A problem is presented in regard to the high likelihood that poor meshing will occur, a bearing will malfunction, or other adverse circumstances will arise.
In the case that a robot hand is used in a clean room, a lubricant that has been supplied or applied to the bearing sections and bevel gear meshing sections in the joint sections will be scattered, and a problem will be presented in that the cleanliness of the clean room will be compromised.